In mobile communication systems defined by 3GPP in the related art, when serving gateway apparatuses (S-GWs) detect congestion, an instruction to perform access barring is configured to be given to eNBs (radio base stations).
Specifically, the eNBs receiving this instruction are configured to notify UEs (mobile stations) of a barring time and the UEs are configured not to perform call request processes until the barring time expires.